A tape cartridge having a leader block provided therein has been used for a magnetic instrument such as a magnetic storage, for example, which is provided as a peripheral equipment for a computer to back up informations. The leader block is connected to a leader end of a tape wound on a single reel in the tape cartridge to guide the tape along a predetermined guide path to a winding reel in the magnetic instrument while it is associated with a drawing pin mechanism in the magnetic instrument.
Such a drawing pin mechanism is disclosed in Japanese Application Publication No. 13,097/1984, for example. In the prior art, the magnetic instrument has a full space in the positional relation of the tape cartridge, a magnetic head, a winding reel and tape guide means while the drawing pin mechanism has a large linkage used therein, which causes the whole apparatus to have a large size.
However, the peripheral equipment for the computer has been compacted, which requires the magnetic instrument to be also compacted. Compactness of the magnetic instrument is accomplished by a complicated arrangement of the tape cartridge, the magnetic head, the winding reel and the tape guide means and also by a complicated tape running path and a complicated drawing pin guide path provided along the complicated tape running path. This disadvantageously accompanies an acute curve portion of the drawing pin guide path. Furthermore, the drawing pin member is required to be smoothly guided along the complicated guide path. However, there have been produced various technical problems for compacting a drawing pin drive mechanism while such a requirement is met. For example, with the linkage having a construction in which it is extended to a maximum length at the the acute curve portion of the guide path, the drawing pin member has little drive power applied thereto at that position, which causes the drawing pin member to be moved in a backward direction to its original position due to a tape tension applied thereto.